The Respiratory System
Key Concepts
_ What are the functions of the respiratory system?
_ What structures does air pass through as it travels to the lungs?
_ What happens during gas exchange and breathing?
The Respiratory System
Key Concepts
_ What are the functions of the respiratory system?
_ What structures does air pass through as it travels to the lungs?
_ What happens during gas exchange and breathing?
The respiratory system moves oxygen from the outside environment into
the body. It also removes carbon dioxide and water from the body.
Respiration is the process in which oxygen and glucose undergo a
complex series of chemical reactions inside cells. Respiration, which is also
called cellular respiration, releases the energy that fuels growth and other
cell processes. Respiration is different from breathing, which is the
movement of air into and out of the lungs. Respiration also produces carbon
dioxide and water, which are eliminated by the respiratory system.
The respiratory system moves oxygen from the outside environment into
the body. It also removes carbon dioxide and water from the body.
Respiration is the process in which oxygen and glucose undergo a
complex series of chemical reactions inside cells. Respiration, which is also
called cellular respiration, releases the energy that fuels growth and other
cell processes. Respiration is different from breathing, which is the
movement of air into and out of the lungs. Respiration also produces carbon
dioxide and water, which are eliminated by the respiratory system.
As air travels from the outside environment to the lungs, it passes
through the following structures: nose, pharynx, trachea, and bronchi. Air
enters the body through your nostrils and then moves into the nasal cavities.
Some of the cells lining the nasal cavities produce mucus. Mucus cleans,
warms, and moistens air you breathe. The inside of the nose is lined with
cilia. Cilia (singular cilium) are tiny hairlike extensions that can move
together. They sweep the mucus into the throat where it is swallowed.
Air moves from the nose downward into the throat, or pharynx. The
trachea, or windpipe, leads from the pharynx to the lungs. The walls of the
trachea are made of rings of cartilage that keep it open. The trachea is lined
with cilia and mucus. The cilia in the trachea move the mucus toward the
pharynx, where it is swallowed.
As air travels from the outside environment to the lungs, it passes
through the following structures: nose, pharynx, trachea, and bronchi. Air
enters the body through your nostrils and then moves into the nasal cavities.
Some of the cells lining the nasal cavities produce mucus. Mucus cleans,
warms, and moistens air you breathe. The inside of the nose is lined with
cilia. Cilia (singular cilium) are tiny hairlike extensions that can move
together. They sweep the mucus into the throat where it is swallowed.
Air moves from the nose downward into the throat, or pharynx. The
trachea, or windpipe, leads from the pharynx to the lungs. The walls of the
trachea are made of rings of cartilage that keep it open. The trachea is lined
with cilia and mucus. The cilia in the trachea move the mucus toward the
pharynx, where it is swallowed.
Air moves from the trachea into the bronchi (singular bronchus). The
bronchi are passages that direct air into the lungs. The lungs are the main
organs of the respiratory system. Inside the lungs, each bronchus divides
into smaller and smaller tubes. At the end of the smallest tubes are bunches
of alveoli (singular alveolus). Alveoli are tiny sacs of lung tissue specialized
for the movement of gases between air and blood. Alveoli are surrounded by
capillaries. After air enters an alveolus, oxygen passes through the wall of
the alveolus and then through the capillary wall into the blood. Carbon
dioxide and water pass from the blood into the alveoli. This process is
known as gas exchange.
Air moves from the trachea into the bronchi (singular bronchus). The
bronchi are passages that direct air into the lungs. The lungs are the main
organs of the respiratory system. Inside the lungs, each bronchus divides
into smaller and smaller tubes. At the end of the smallest tubes are bunches
of alveoli (singular alveolus). Alveoli are tiny sacs of lung tissue specialized
for the movement of gases between air and blood. Alveoli are surrounded by
capillaries. After air enters an alveolus, oxygen passes through the wall of
the alveolus and then through the capillary wall into the blood. Carbon
dioxide and water pass from the blood into the alveoli. This process is
known as gas exchange.
The diaphragm is a large, dome-shaped muscle at the base of the lungs.
When you breathe, the actions of your rib muscles expand or contract your
chest, causing air to flow in or out.
The diaphragm is a large, dome-shaped muscle at the base of the lungs.
When you breathe, the actions of your rib muscles expand or contract your
chest, causing air to flow in or out.
The larynx, or voice box, is located at the top of the trachea. Your vocal
cords are two folds of connective tissue that stretch across the opening of the
larynx. The vocal cords vibrate when air passes over them. This produces the
sound of your voice.
The larynx, or voice box, is located at the top of the trachea. Your vocal
cords are two folds of connective tissue that stretch across the opening of the
larynx. The vocal cords vibrate when air passes over them. This produces the
sound of your voice.